- The following are certain facts regarding bioremediation:
A. Biodegradable plastics are made using polyhydroxy alkanoates (PHAs) such as
polyhydroxybutyrate (PHB).
B. Pseudomonas putida F1 bacterial strain is involved in degradation of aromatic hydrocarbon.
C. The bacterium Deinococcus radiodurans consume and digest toluene and ionic mercury from highly radioactive nuclear waste.
D. Bioaugmentation is a process of improving environment of the microorganisms already existing in the system for degradation of xenobiotic compound.
Which one of the following combination of above statements is correct?
(1) A, B and C (2) A, B and D
(3) A, C and D (4) B, C and DStatement-wise explanation
A. Biodegradable plastics and PHAs – Correct
Polyhydroxyalkanoates (PHAs), including polyhydroxybutyrate (PHB), are microbial polyesters that are biodegradable and used to make bioplastics.
So statement A is correct.B. Pseudomonas putida F1 and aromatic hydrocarbons – Correct
Pseudomonas putida F1 is a well-studied strain capable of metabolizing several aromatic hydrocarbons such as toluene, benzene, and ethylbenzene via toluene dioxygenase and related pathways.
Thus B is also correct.C. Deinococcus radiodurans, toluene and mercury – Correct
Wild-type Deinococcus radiodurans is extremely radiation resistant; genetically engineered strains have been made that can detoxify ionic mercury and degrade toluene in mixed radioactive wastes.
The statement notes that the bacterium “consume and digest toluene and ionic mercury from highly radioactive nuclear waste,” which matches the function of these engineered strains, so C is considered correct in this context.D. Definition of bioaugmentation – Incorrect
The statement describes bioaugmentation as “improving environment of the microorganisms already existing in the system.”
That is actually the definition of biostimulation, where nutrients or electron acceptors/donors are added to stimulate indigenous microbes.
Bioaugmentation instead means adding selected microbial cultures (bacteria, archaea, etc.) to the site to enhance degradation.
Hence D is incorrect.
Since A, B and C are correct and D is incorrect, the right option is (1) A, B and C.
